Abstract ? The Patient Registry-Virtual Biorepository Core will support collection of human esophageal specimens for use in the Center's translational research projects as well as for the centralized BETRNet program's virtual repository to be located at the BETRNet Coordinating Center. This Core will provide capabilities for timely sharing of specimen data with the BETRNet Coordinating Center for trans-BETRNet specimen management. This Core will provide clinical data, banked serum, plasma, somatic DNA, frozen mucosal specimens, and formalin-fixed paraffin-embedded (FFPE) mucosal specimens from a cross-sectional cohort of patients with and without BE. This Core will also provide data from a cross-sectional cohort of patients in a continuum from BE to EAC in order to facilitate identification of promising cell surface targets. This Core will also maintain, update, and provide clinical data and FFPE mucosal specimens from a longitudinal cohort of patients with BE, including those who progress to neoplasia.